1. Field of the Invention
Apparatuses and methods consistent with the present invention relate to a semiconductor probe having a resistive tip and a method of fabricating the same, and more particularly, to semiconductor probe in which a dielectric layer that protects a resistive tip and an electric field shield for increasing resolution form a plane on an apex of the resistive tip, and a method of fabricating the same.
2. Description of the Related Art
With the increase in demand for small electronic devices such as mobile communication terminals and personal digital assistants comes the need for ultra small highly integrated recording media. However, since further miniaturization of a related art hard disk is not easy, and higher integration of a flash memory is also difficult, scanning probe storage is being investigated as an alternative method of information storage.
A scanning probe is used for various scanning probe microscopy (SPM) techniques. Examples of these are a scanning tunneling microscope (STM) that generates information by detecting a current that flows according to a voltage difference applied between a scanning probe and a specimen, an atomic force microscope (AFM) that uses an atomic force between a scanning probe and a specimen, a magnetic force microscope (MFM) that uses a magnetic force between a magnetic field of a specimen and a magnetized scanning probe, a scanning near-field optical microscope (SNOM) that overcomes the resolution limit of visible light, and an electrostatic force microscope (EFM) that uses an electrostatic charge between a specimen and a scanning probe.
In order to read and write information at high speed and high density using SPM techniques, the scanning probe must be able to detect the surface charge of a region as small as a few tens of nanometers in diameter. Also, in order to increase the read and write speed, cantilevers must be fabricated in an array.
FIG. 1 is a cross-sectional view of a cantilever 70 having a resistive tip 50 disclosed in International Patent Publication No. WO 03/096409. The resistive tip 50 is formed vertically on the cantilever 70 that may be fabricated in an array, and may have a resistance region 56 with a diameter of a few tens of nanometers.
Referring to FIG. 1, the resistive tip 50 of a semiconductor probe includes a main body 58 doped with a first impurity, the resistance region 56, located on an apex portion of the resistive tip 50 and doped with a low concentration of a second impurity, and first and second semiconductor electrode regions 52 and 54 which are located on both side slopes of the main body 58 and are doped with a high concentration of the second impurity.
However, in the semiconductor probe having the resistive tip 50, the regions of the slopes of the first and second semiconductor electrode regions 52 and 54 doped with a high concentration may be reduced by excessive etching during a wet etching process for forming the resistive tip 50. Accordingly, the conductive regions on the slopes are reduced, which increases the size and the resistance of the resistance region 56, thereby reducing the spatial resolution with respect to a resistance variation. Also, there is a problem of wear at the end of the resistive tip.
In order to increase the spatial resolution, researches have been conducted for a semiconductor probe having an electric field shield on the slope of a resistive tip. However, although the spatial resolution of this type of semiconductor probe can be increased, its performance is reduced due to friction of the resistive tip.